The maximum allowable global loop gain of a charge pump-based PLL typically decreases in accordance with a decrease of the frequency of an input signal for the PLL. The loop stability of a PLL can be maintained by varying the loop gain of the PLL in response to changes in the frequency of the input signal. Varying the loop gain for the purpose of maintaining loop stability can be a problem in situations where a circuit is constrained from using additional input or output pins.
An appreciation of the present invention and its improvements can be obtained by reference to the accompanying drawings, which are briefly summarized below, to the following detailed description of illustrated embodiments of the invention, and to the appended claims.